Diagnostic test for renal injury

Abstract

A method is provided of diagnosing and monitoring acute renal injury leading to acute renal failure in a human or mammalian subject by determining the ratio of the concentration of neutrophil gelatinase-associated lipocalin (NGAL) in urine to that in plasma or serum.

1. A method of diagnosing the presence of renal injury that has led to acute renal failure or which signifies an immediate risk of developing acute renal failure in a human individual, said method comprising the steps of
 i) determining the concentration of neutrophil gelatinase-associated lipocalin (NGAL) in a sample of urine taken from the individual; 
 ii) determining the concentration of NGAL in plasma or serum from a sample of blood taken from the same individual immediately before, during or immediately after the urine sample was collected; 
 iii) calculating the ratio of the NGAL concentration in the urine to that in the plasma or serum and comparing the value of the ratio obtained with a cutoff value determined from individuals of the same species without evidence of renal injury, 
 iv) diagnosing the presence of the renal injury when the ratio has a value greater than the cutoff value, wherein the cutoff value is a value of at least 0.30 or higher. 
 
     
     
       2. The method of  claim 1 , comprising the further step of repeating steps i), ii) and iii) of  claim 1  one or more times. 
     
     
       3. The method of  claim 1 , comprising the further step of repeating steps i), ii) and iii) of  claim 1  within 24 hours. 
     
     
       4. The method of  claim 1 , comprising the further step of repeating steps i), ii) and iii) of  claim 1  after a treatment of acute renal failure has been initiated or completed. 
     
     
       5. The method of  claim 1 , wherein the risk of developing acute renal failure is due to ischemic renal injury. 
     
     
       6. The method of  claim 1 , wherein the risk of developing acute renal failure is due to a complication of an inflammatory, infective or neoplastic disease. 
     
     
       7. The method of  claim 1 , wherein the risk of developing acute renal failure is due to critical illness of any cause requiring intensive care. 
     
     
       8. The method of  claim 1 , wherein the risk of developing acute renal failure is due to a surgical intervention. 
     
     
       9. The method of  claim 1 , wherein the risk of developing acute renal failure is due to the administration of a nephrotoxic agent. 
     
     
       10. The method of  claim 1 , wherein NGAL is measured by means of an antibody that binds specifically to human NGAL. 
     
     
       11. The method of  claim 1 , wherein said cutoff value is a value of at least 0.73 or higher. 
     
     
       12. The method of  claim 1 , wherein said cutoff value is a value of at least 1.14 or higher. 
     
     
       13. A method of diagnosing the presence of renal injury that has led to acute renal failure or which signifies an immediate risk of developing acute renal failure in a human individual, said method comprising the steps of
 i) determining the concentration of NGAL in a sample of urine taken from the individual; 
 ii) determining the concentration of NGAL in plasma or serum from a sample of blood taken from the same individual immediately before, during or immediately after the urine sample was collected; 
 iii) calculating the ratio of the NGAL concentration in the plasma or serum to that in the urine and comparing the value of the ratio obtained with a cutoff value determined from individuals of the same species without evidence of renal injury, 
 iv) diagnosing the presence of the renal injury when the ratio has a value lower than the cutoff value, wherein the cutoff value is a value of 3.33 or lower. 
 
     
     
       14. The method of  claim 13 , comprising the further step of repeating steps i), ii) and iii) of  claim 13  one or more times. 
     
     
       15. The method of  claim 13 , comprising the further step of repeating steps i), ii) and iii) of  claim 13  within 24 hours. 
     
     
       16. The method of  claim 13 , comprising the further step of repeating steps i), ii) and iii) of  claim 13  after a treatment of acute renal failure has been initiated or completed. 
     
     
       17. The method of  claim 13 , wherein the risk of developing acute renal failure is due to ischemic renal injury, a complication of an inflammatory, infective or neoplastic disease, a critical illness of any cause requiring intensive care, a surgical intervention, or the administration of a nephrotoxic agent. 
     
     
       18. The method of  claim 13 , wherein NGAL is measured by means of an antibody that binds specifically to human NGAL. 
     
     
       19. The method of  claim 13 , wherein said cutoff value is a value of 1.37 or lower. 
     
     
       20. The method of  claim 13 , wherein said cutoff value is a value of 0.88 or lower.